As cosmetic surgery booms, women have left the lucrative profession almost entirely to men.

When Stephanie Hallberg was 16, she decided she wanted to reduce the size of her breasts. Then years later after visits with doctors—all men, all of whom recommended she keep her breasts the way they were—she found a doctor who sympathized with her predicament and agreed to perform the surgery, Dr. Michelle Copeland, who works out of a Fifth Avenue office complete with its own operating room.

"I couldn't even imagine going to a man for any plastic surgery," Ms. Hallberg, 26, said. "A man can study the woman's body forever, but I believe he can never really understand how a woman is put together, mentally, emotionally, physically."

Ms. Hallberg is lucky to have found a plastic surgeon who is a woman, since they are indeed a rarity—only about 4 percent of all the board-certified plastic surgeons in the United States, according to the American Society for Aesthetic Plastic Surgery. In New York, the disparity is even greater: of approximately 500 board-certified plastic surgeons, only 12 are women, and only about half of those spend the bulk of their time practicing cosmetic surgery.